Wireless networks use a large number of individual base stations or cells to provide high capacity wireless services over large coverage areas such as market areas (e.g. cities), surrounding residential areas (e.g. suburbs, counties), highway corridors and rural areas. Continuous radio connectivity across these large coverage areas is accomplished via user mobility from one base station to others as the user traverses the network's operating area. Optimization of such networks is traditionally performed manually by network management personnel responsible for monitoring run time network performance and making changes to system configuration parameters in attempts to improve network performance and to respond to real time events such as cell outage, cell load imbalances, etc.
Recently technologies have been introduced to automate many of these traditionally manual network management tasks. These technologies, often collectively referred to as Self Organizing Network (SON) technologies, use automated processes carried out by hardware and software that continually monitor network performance and take corrective action in the case of particular network events. Examples include temporary compensation for cell outages, automated maintenance of wireless base station neighbor cell lists, autonomous network load balancing between highly loaded and lightly loaded neighboring cells, and many other automation use cases.
Practical SON systems must support multiple simultaneous SON automation software processes which may be referred to as SON Application Programs, or simply SON apps. In typical operation a SON system may be simultaneously executing a variety of independent SON apps. For example, a SON system may simultaneously execute an application monitoring and waiting to take corrective action for cell outage, an application monitoring and waiting to take action for load balancing, another application periodically updating neighbor list parameters, etc.
Running applications simultaneously may cause conflicts in a system. Multiple SON applications altering configuration parameters at the same network elements (e.g. wireless system base station cells) at the same time or in close succession to one another may lead to system instability problems and endless loops of parameter adjustments performed by multiple SON processes.
Attempts to maintain long term parameter defaults to the latest ‘as optimized’ configuration are complicated by the existence of multiple automated optimization modules operating across different time frames. Optimizations dealing with transient load imbalances and temporary compensation for out of service network cells operate in shorter time frames, while long term network optimization processes operate in longer time frames. Conflicts between multiple processes may cause system instability in a multi-process automation environment.